Non-invasive imaging technologies allow images of the internal structures or features of a subject (patient, manufactured good, baggage, package, or passenger) to be obtained non-invasively. In particular, such non-invasive imaging technologies rely on various physical principles, such as the differential transmission of X-rays through the target volume or the reflection of acoustic waves, to acquire data and to construct images or otherwise represent the internal features of the subject.
By way of example, computed tomography (CT) imaging systems are used to generate images in a non-invasive manner by acquiring X-ray transmission data over a range of angular views about a patient and reconstructing the measured data to generate volumetric or cross-sectional views of the patient. Such computed tomography approaches may be used for medical imaging, as well as for certain industrial or security screening applications.
In CT, a portion of the radiation passes through the subject or object and impacts a detector, where representative signals are acquired. To acquire data over a useful angular range, data is acquired nearly continuously by the detector over the course of an examination, in contrast to conventional radiography, where the detector only acquired data at discrete acquisitions or shots. As a result, certain requirements are placed on a CT detector that are not necessary for other detectors where less continuous types of data collection occur. In particular, to facilitate rapid readout, each pixel of the detector typically has its own readout channel, resulting in a massively parallel readout architecture. Such architectures, however, may impose their own corresponding issues, such as noise associated with the distance the analog signals must travel prior to digitization and, in arrangements where the digital conversion circuitry is placed near to the photodiode structures generating the signals, the heat from these circuits may degrade the performance of the detection circuitry.